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Black Hole

A black hole is an astronomical object whose gravity is so strong that nothing—even light—can escape from within its event horizon. It forms when a massive star’s core collapses or through other processes, and may have an accretion disk of infalling matter that emits radiation. Supermassive black holes at galaxy centers influence stellar orbits, and mergers produce gravitational waves.

Source: nasa.gov

APODs including "Black Hole"

Jet Near Light Speed

24/11/1997

Jet Near Light Speed
Image Credit: NASA Astronomy Picture of the Day

stein's Special Theory of Relativity says that nothing can travel faster than the speed of light. Jets of protons and electrons that shoot away from objects such as quasars and black holes appear to travel at speeds approaching this maximum speed, though. Such jets carry tremendous energy and can ram straight through interstellar material. In the above frame from a computer simulation, a jet traveling only 98 percent of light speed rams and mixes with interstellar material. Even higher energy jets might well explain the structure seen around Cygnus A.